A tripod and laser head assembly provides a stable platform for an arrangement of laser diodes to project a number of laser lines therefrom. The lasers can have numerous uses, from surveying to leveling. In the case of leveling, the laser light beam is projected onto the surface of an object in order to provide a perfectly horizontal line thereon. For example, a laser leveler may be employed to hang pictures on a wall evenly, level a joist or beam during construction, or for marking a line.
Typically, a laser leveler has but a single laser source that projects a single horizontal light beam outwards. Depending on the distance from the laser source to the surface of the object that the light beam is being projected onto, a single laser source can only provide an arc of laser light less than 180°. In practice, this results in a horizontal line projected on the surface of the object that is limited in length. In order to project a visible light line on a surface of an object without a limitation as to line length, for example projecting a continuous light beam on four walls in a square room, more than one laser source must be employed.
However, calibrating more than one laser source in a single device can be difficult. When leveling or calibrating a laser light beam, in order to provide a truly horizontal line, six adjustment factors must be considered. The first three adjustment factors include an X axis, a Y axis and a Z axis (corresponding to the three movement directions in space). The X, Y and Z directions may be calibrated by adjusting the height of the laser sources for the Z axis, and by using a pendulum to calibrate the X and Y axes. The next three factors of calibration include rotation about the X axis, i.e. roll, rotation about the Y axis, i.e. pitch, and rotation about the Z axis, i.e. yaw. When using a single light source, roll, pitch and yaw may be adjusted by simply adjusting various parts of the laser light source. However, when utilizing a plurality of light sources, adjusting the roll, pitch and yaw is more difficult.
Accordingly, the present invention seeks to provide a laser calibration apparatus useful for a plurality of laser light sources and a method of calibrating the plurality of laser light sources.